Gun bolt

ABSTRACT

A gun bolt stem is provided which completely fills the extractor groove of the case during firing of the round of ammunition.

United States Patent 1191 Clark Nov. 19, 1974 GUN BOLT [75] Inventor: Burton Parker Clark, Saint George,

[73] Assignee: General Electric Company,

Burlington, Vt.

[22] Filed: July 23, 1973 [21] App]. No.: 381,952

[52] US. Cl. 42/25, 89/9 [51] Int. Cl F4lc 15/00, F4ld 7/02 [58] Field of Search 42/25; 89/9, 11, 12, 13

[56] References Cited UNITED STATES PATENTS 2,473,373 6/1949 Howell 42/25 2,585,195 2/1952 Walker 42/25 3,253,362 5/1966 Gitchell 42/25 3,690,215 9/1972 Clark et a]. 89/12 Primary Examiner-Samuel Feinberg Assistant Examiner-C. T. Jordan Attorney, Agent, or FirmBailin L. Kuch [5 7] ABSTRACT A gun bolt stem is provided which completely fills the extractor groove of the case during firing of the round of ammunition.

6 Claims, 7 Drawing Figures e non si GUN BOLT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to gun bolts for use with rounds of ammunition having a case with an extractor groove; and is especially adapted to such cases made of relatively weak material such as plastic.

2. Description of the Prior Art Modern, conventional, cased ammunition has a metal case of the configuration shown, for example, in U.S. Pat. No. 3,498,221 issued to Hilton, et al, on Mar. 3, 1970. Various proposals have been made to make such cases out of plastic, but apparently the only significant use of plastic has been in shot gun shell cases as discussed, for example, in U.S. Pat. No. 3,678,858 issued to Herter, et al, on July 25, 1972. This may be due to the fact that when plastic is substituted for metal in a case having an extractor groove, the plastic is not strong enough to alone withstand the internal pressures of the explosion, and requires support over all of its external surfaces to preclude rupture.

BRIEF SUMMARY OF THE INVENTION It is an object of this invention to provide a gun bolt and chamber system which fully supports a case having an extractor groove.

A feature of this invention is the provision of a gun .bolt system which completely fills the extractor groove of the case duringfiring of the round of ammunition.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features and advantages of this invention will be apparent from the following specification thereof taken in conjunction with the accompanying drawing in which:

FIG. 1 is a view in longitudinal cross-section of a gun bolt and chamber system embodying this invention, taken along the plane I-I of FIG. 2, showing a round being rammed with the bolt unlocked; I

FIG. 2 is a view in transverse cross-section of the system of FIG. 1 taken along the plane 11-" of FIG. 1;

FIG. 3 is a view in longitudinal cross-section of the system of FIG. 1, taken along the plane IIIIII of FIG. 4, showing the round being rammed with the bolt unlocked and the case extractor groove filled;

FIG. 4 is a view in transverse cross-section of the sys tem of FIG. 1 taken along the plane [VIV of FIG. 3;

FIG. 5 is a view in longitudinal cross-section of the system of FIG. 1, similar to FIG. 3, showing the bolt and round fully chambered;

FIG. 6 is a view in longitudinal cross-section of the system of FIG. 1, taken along the plane VI-VI of FIG. 7, showing the bolt locked; and

FIG. 7 is a view intransverse cross-section of the system of FIG. 1, taken along the plane VIIVII of FIG. 6.

THE PREFERRED EMBODIMENT The embodiment of this'invention herein shown and described is as incorporated in the gun having a plurality of barrels and respective bolts shown in U.S. Pat.

No. 3,722,356 issued to D. P. Tassie, et al, on Mar. 27, 1973; and in the bolt locking system shown in U.S. Pat.

No. 3,690,215 issued to B. P. Clark, et al, on Sept. 12, 1972; to which reference should be made for a more complete disclosure of the gun. Alternatively, this invention may be incorporated in an otherwise conventional Gatling type gun of the type shown in U.S. Pat. No. 3,380,343 issued to R. E. Chiabrandy on Apr. 30. 1968.

A bolt assembly 10 including a bolt body 12, a bolt face 14, an extractor lug l6, and a cam follower 18 is disposed for reciprocation in a groove 20 in a receiver 22. The groove is aligned with a chamber 24 which is here shown as part of the receiver but which might conventionally be formed as part of the barrel, not shown, which is fixed into the receiver. The receiver is disposed in a housing 26 having a quasi-elliptical cyclindrical cam slot 30. There is relative rotation between the receiver and the housing.

Two longitudinal tracks 32 are fixed, as by machine screws, not shown, to the receiver and overlie the groove 20 and extend into two respective longitudinal slots 34 in the bolt body to provide longitudinal guidance for the bolt. The bolt cam follower l8 rides in the housing cam slot 30 and serves to reciprocate the bolt between an aft loading and ejection position and a forward locking and firing position.

An irregular depth transverse slot 36 is formed into and about the periphery of the bolt body. A substantially U-shaped lock segment 38 rides in the bolt annular slot. The slot may have two opposed flat surfaces 40, an inner arcuate surface 44, and an outer arcuate surface 46. The lock segment has two opposed flat surfaces 48, an inwardly facing arcuate surface 50, and two opposed outwardly opening cut-outs 52 to accommodate the tracks 32. The extractor lug 16 is a slightly less than semi-annular web encircling and extending from the lower half of the face 14 of the bolt and having two shoulders 53 parallel to and immediately below the level of the slots 34. An arcuate surface 54 of reduced radius extends around the upper part of the bolt from and between the shoulders 53.

A cross-slide 56 is disposed in a transverse slot 58 in the receiver and is bifurcated into two legs 60, each terminating into an inwardly directed foot 62, and encompassing an arcuate surface 64. The cross-slide has a cam follower 66 which rides in a transverse cam slot 68 in the housing, and is adapted to pass into the slot 36 and to straddle the bolt body.

A U-shaped extractor groove filler segment 70 is disposed under the cross-slide 56. The segment has an exterior arcuate surface 72 which mates with the surface 64, and interior aft arcuate surface 74 which mates with the forward upper arcuate surface 54 of the bolt, and an interior forward arcuate surface 76 which mates with the remainder of the extractor groove of the case not occupied by the extractor lug 16.

A self aligning, longitudinally effective catch between the bolt and the filler segment is provided by a projecting ball 78 fixed into the surface 54 of the bolt and a socket 80 formed into the surface 74 of the segment. The distal ends of the filler segment are notched at 82 to receive the ends of the feet 62 of the cross-slide 62, so that, in combination with the extractor lug 16, a full 360 of annulus will fill the extractor groove of the case.

In operation, the round is handed to the bolt when the bolt is in its maximum aft position with the extractor lug 16 entering the extractor groove of the case of the round. The cam slot 30 brings the bolt forward along the guide tracks 32 together with the locking segment 38 through the unlocked position shown in FIGS. 1 and 2. The cam follower 66 of the cross-slide 56 is in the outermost dwell of the cam slot 68 and the filler segment 72 is in its aft position transversely aligned with the raised cross-slide 56, and nestled against a shoulder 84 in the housing. The bolt continues forward through the intermediate position shown in FIGS. 3 and 4. The cam follower 66 pushes the cross-slide down together with the filler segment, so that the filler segment rides off the shoulder 84 and into the extractor groove of the case. The ball and socket catch also interlocks. The bolt continues forward to fully chamber the round as shown in FIG. 5. The extractor groove, and also the ball and socket catch have carried the filler segment forward of the cross-slide 56 into a recess 86 in the receiver, and the cam follower 66 has reached the end of the middle dwell. The cam follower 66 now pushes the cross-slide 56 down in part into the slot 36 in the bolt, while the cross-slide 56 pushes the locking segment down in part into the slot 58 in the receiver, thus providing 360 of lock around the bolt. Meanwhile the extractor lug l6 and the filler segment provide 360 of support in and around the extractor groove of the case, the lug being supported by the wall of the groove 20, and the segment being supported by the 'wall of the recess 86. After the round has been fired, the cam follower rides up into the middle'dwell, raising the crossslide to the position shown in FIG. 5, lining up its feet 62 with the notches 52. As the cam track- 30 traverses the bolt aft, the extractor lug pulls the case aft, and the case pushes the filler segment aft to the position shown in FIG. 3. If a case is absent, then the ball and socket catch serves to bring the filler segment aft. After the cam follower 66 rides into the outer dwell, raising the cross-slide and the filler segment to the position shown in FIG. 1, the bolt rides out from under the cross-slide to eject the fired case.

What is claimed is:

l. A bolt assembly, for a firearm, for firing a round of ammunition having a peripheral extractor groove, said assembly comprising:

a receiver having a chamber having an interior wall;

a bolt longitudinally slidable in said receiver and haw ing an extractor lug for disposition within an initial. angularly defined. portion of the extractor groove of the round;

a filler segment for disposition within the remainder. angularly defined. portion of the extractor groove of the round; and

transport means for initially disposing said filler segment within the remainder portion of the extractor groove and for subsequently disposing both said filler segment and said extractor lug within said chamber in transverse adjustment with said interior wall. whereby the extractor groove is substantially filled and supported over its full 360 of angular extent.

2. An assembly according to claim I, wherein:

said transport means includes a cross-slide transversely slidable in said receiver for inserting and withdrawing said filler segment into and out of the extractor groove.

3. An assembly according to claim 2, wherein: said transport means further includes cam means for reciprocating said cross-slide transversely. y

4. An assembly according to claim 3, whereby: said transport means further includes additional cam means for reciprocating said bolt longitudinally. I

5. An assembly according to claim I, wherein: said transport means includes interlock means for releasably securing said filler segment to said bolt against relative longitudinal movement therewith. whereby said bolt is adapted to carry said filler segment longitudinall therewith.

6. An assembly according to claim 2, wherein: said transport means includes additional interlock means for releasably securing said fillersegment to said cross-slide, whereby said cross-slide is adapted to carry said filler segment transversely therewith. 

1. A bolt assembly, for a firearm, for firing a round of ammunition having a peripheral extractor groove, said assembly comprising: a receiver having a chamber having an interior wall; a bolt longitudinally slidable in said receiver and having an extractor lug for disposition within an initial, angularly defined, portion of the extractor groove of the round; a filler segment for disposition within the remainder, angularly defined, portion of the extractor groove of the round; and transport means for initially disposing said filler segment within the remainder portion of the extractor groove and for subsequently disposing both said filler segment and said extractor lug within said chamber in transverse adjustment with said interior wall, whereby the extractor groove is substantially filled and supported over its full 360* of angular extent.
 2. An assembly according to claim 1, wherein: said transport means includes a cross-slide transversely slidable in said receiver for inserting and withdrawing said filler segment into and out of the extractor groove.
 3. An assembly according to claim 2, wherein: said transport means further includes cam means for reciprocating said cross-slide transversely.
 4. An assembly according to claim 3, whereby: said transport means further includes additional cam means for reciprocating said bolt longitudinally.
 5. An assembly according to claim 1, wherein: said transport means includes interlock means for releasably securing said filler segment to said bolt against relative longitudinal movement therewith, whereby said bolt is adapted to carry said filler segment longitudinall therewith.
 6. An assembly according to claim 2, wherein: said transport means includes additional interlock means for releasably securing said filler segment to said cross-slide, whereby said cross-slide is adapted to carry said filler segment transversely therewith. 